Question

Cho hệ pt:\(\left\{{}\begin{matrix}x+my=m+1\\\\mx+y=2m\end{matrix}\right.\)

1)Giải hpt khi m=2

2)Tìm m để hpt thỏa mãn \(\left\{{}\begin{matrix}x\ge2\\\\y\ge1\end{matrix}\right.\)

Answer 1

thay m=2 vào HPT ta có
\(\left\{{}\begin{matrix}x+2y=2+1\\2x+y=2.2\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x+2y=3\\2x+y=4\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}2x+4y=6\\2x+y=4\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}3y=2\\2x+y=4\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{5}{3}\\y=\dfrac{2}{3}\end{matrix}\right.\)
vậy ..........